Add doc for llamacpp example

Author: mreso

examples/cpp/llamacpp/README.md

@@ -0,0 +1,86 @@
+This example used [llama.cpp](https://github.com/ggerganov/llama.cpp) to deploy a Llama-2-7B-Chat model using the TorchServe C++ backend.
+The handler C++ source code for this examples can be found [here](../../../cpp/src/examples/llamacpp/).
+
+### Setup
+1. Follow the instructions in [README.md](../../../cpp/README.md) to build the TorchServe C++ backend.
+
+```bash
+cd ~/serve/cpp
+./builld.sh
+```
+
+2. Download the model
+
+```bash
+cd ~/serve/examples/cpp/llamacpp
+curl -L https://huggingface.co/TheBloke/Llama-2-7B-Chat-GGUF/resolve/main/llama-2-7b-chat.Q5_0.gguf?download=true -o llama-2-7b-chat.Q5_0.gguf
+```
+
+4. Create a [config.json](config.json) with the path of the downloaded model weights:
+
+```bash
+echo '{
+"checkpoint_path" : "/home/ubuntu/serve/examples/cpp/llamacpp/llama-2-7b-chat.Q5_0.gguf"
+}' > config.json
+```
+
+5. Copy handle .so file
+
+While building the C++ backend the `libllamacpp_handler.so` file is generated in the [llamacpp_handler](../../../cpp/test/resources/examples/llamacpp/llamacpp_handler) folder.
+
+```bash
+cp ../../../cpp/test/resources/examples/llamacpp/llamacpp_handler/libllamacpp_handler.so ./
+```
+
+### Generate MAR file
+
+Now lets generate the mar file
+
+```bash
+torch-model-archiver --model-name llm --version 1.0 --handler libllamacpp_handler:LlamaCppHandler --runtime LSP --extra-files config.json
+```
+
+Create model store directory and move the mar file
+
+```
+mkdir model_store
+mv llm.mar model_store/
+```
+
+### Inference
+
+Start torchserve using the following command
+
+```
+torchserve --ncs --model-store model_store/
+```
+
+Register the model using the following command
+
+```
+curl -v -X POST "http://localhost:8081/models?initial_workers=1&url=llm.mar&batch_size=2&max_batch_delay=5000"
+```
+
+Infer the model using the following command
+
+```
+curl http://localhost:8080/predictions/llm -T prompt1.txt
+```
+
+This example supports batching. To run batch prediction, run the following command
+
+```
+curl http://localhost:8080/predictions/llm -T prompt1.txt & curl http://localhost:8080/predictions/llm -T prompt2.txt &
+```
+
+Sample Response
+
+```
+Hello my name is Daisy. Daisy is three years old. She loves to play with her toys.
+One day, Daisy's mommy said, "Daisy, it's time to go to the store." Daisy was so excited! She ran to the store with her mommy.
+At the store, Daisy saw a big, red balloon. She wanted it so badly! She asked her mommy, "Can I have the balloon, please?"
+Mommy said, "No, Daisy. We don't have enough money for that balloon."
+Daisy was sad. She wanted the balloon so much. She started to cry.
+Mommy said, "Daisy, don't cry. We can get the balloon. We can buy it and take it home."
+Daisy smiled. She was so happy. She hugged her mommy and said, "Thank you, mommy!"
+```